Initial stage of tandem contact in Platycnemis pennipes (Pallas) (Zygoptera: Platycnemididae)

The behaviour of the 3 during the initial stage of tandem contact was photo- and videorecorded in the experiments with 2 models in their natural habitats. The <3 holds the 2 at the dorso-posterior edge of her head with its mouthparts, and at the lateral walls of the pronotum with the fore legs. The geometrical centre of the triangle of the 3 points of support is situated along the 2 longitudinal body axis in the region of the 2 mesostigmal plate. It is suggested that the initial stage of tandem contact provides the tactile orientation for the subsequent tandem formation.